This invention relates to the field of therapeutics for the treatment of pain or a dopamine dysregulation disease, such as addiction.
Dopamine is one of the principal neurotransmitters in the central nervous system, where it is involved with motor function, perception, arousal, motivation and emotion. Abnormalities in dopaminergic neurotransmission have been implicated in various neurological and psychiatric disorders, including drug dependence. It has been found that addicting drugs such as nicotine, cocaine, amphetamine, methamphetamine, ethanol, heroin, and morphine enhance (in some cases directly, in other cases indirectly or even trans-synaptically) dopamine (DA) within the mesotelencephalic reward/reinforcement circuitry of the forebrain, presumably producing the enhanced brain reward that constitutes the drug user's “high.” Alterations in the function of these DA systems have also been recovering addicts. For example, cocaine acts on these DA systems by binding to the dopamine transporter (DAT) and preventing DA reuptake into the presynaptic terminal and its indirect dopamine agonist effects are thought to be important for its addictive nature. Ritz et al., Science 237:1219 (1987).
There is a need for new therapeutic agents and methods for the treatment of dopamine dysregulation diseases. Such agents could be used, for example, to relieve a patient's craving for addictive drugs by changing the pharmacological actions of these drugs in the central nervous system.